Mauri J

Risk of thrombosis during coronary angioplasty with low osmolality contrast media

Studies in vitro have suggested that nonionic low osmolar contrast agents produce an increase in thrombogenicity. To determine the incidence of thrombi related to the use of nonionic low osmolar contrast media during coronary angioplasty, a double-blind randomized study was performed in 100 patients. Medication before angioplasty included oral aspirin (250 mg/day) in all cases. At the beginning of the procedure, aspirin (250 mg) and heparin (10,000 U) were intravenously administered. During the procedure patients were randomly assigned to receive either an ionic low osmolar contrast agent ioxaglate (n = 50), or a nonionic low osmolar contrast media iohexol (n = 50). The presence of thrombus was evaluated on the angiogram and on the guidewire immediately after its retrieval from the patients. Clinical, angiographic and procedural variables were similar in the 2 randomized groups. Angiographic evidence of thrombus was observed in 1 patient (2%) assigned to ioxaglate and in 11 patients (22%) assigned to iohexol (p less than 0.005). One patient (2%) from the ioxaglate group and 6 patients (12%) from the iohexol group showed thrombotic residues on the guidewire (p = not significant). Three patients had acute myocardial infarction, 1 patient (2%) receiving ioxaglate and 2 patients (4%) iohexol (p = not significant). There were no deaths. Thus, compared with an ionic low osmolar contrast media ioxaglate, the nonionic low osmolar contrast agent iohexol increases the incidence of thrombus during coronary angioplasty.

Early dysfunction and long-term improvement in endothelium-dependent vasodilation in the infarct-related artery after thrombolysis☆

OBJECTIVES This study assessed the degree of endothelial dysfunction in post-acute myocardial infarction (AMI) and its subsequent status in the infarct-related artery (IRA) in patients treated with thrombolysis. BACKGROUND Coronary flow reserve alterations in the IRA after thrombolysis have been described, but the endothelium-dependent vasomotion has not been investigated, to date. METHODS Endothelial function in patients after thrombolysis was assessed by infusion of acetylcholine (ACh) at increasing doses in the IRA. Diameter changes in the distal segments were evaluated using quantitative coronary angiography. Patients with coronary atherosclerosis constituted the control group. Clinical variables, electrocardiography and biochemical markers were used to determine the timing of reperfusion and the extent of the infarct. Patients in the AMI group were re-evaluated one year later. RESULTS In the initial assessment, 16 patients showed a vasoconstriction response to ACh in the IRA compared to the control group (-20 +/- 21% vs. 4 +/- 4%; p < 0.01). Significant correlations between the degree of vasoconstriction and maximum value of the creatine kinase-MB fraction and number of new Q waves were observed. Of the 12 patients re-evaluated, 4 had complete occlusion of the IRA. In the remaining eight patients with patent artery, an improvement in response to ACh was observed relative to the initial study (+3 +/- 11%, vs. -19 +/- 15%, p < 0.05). CONCLUSIONS In patients with AMI treated with thrombolysis, severe endothelial dysfunction in the IRA is observed early. In patients who retain patency of the IRA, the endothelial dysfunction improves during the follow-up and suggests a component of stunned endothelium in the first few days post-AMI.

Predictive factors and long-term evolution of early endothelial dysfunction after cardiac transplantation☆

BACKGROUND Abnormal coronary vasomotion appears to be a common finding after heart transplantation (HTx). However, the pathophysiology and outcome of this functional disturbance remains poorly understood. Aims of the study were to determine the prevalence, predictive factors and long-term evolution of endothelial dysfunction after cardiac transplantation. METHODS The endothelium-dependent coronary vasomotion of 50 patients, who showed angiographically normal coronary arteries, were studied early (at 3 +/- 1 months) and at follow-up (16 +/- 5 months) after HTx. Endothelial function was studied by selective infusion of serial doses of acetylcholine (ACh) (10(-8), 10(-7)and 10(-6) mol/l) in the left anterior descending coronary artery. Changes in mean luminal diameter after the infusion of each dose were evaluated by quantitative coronary angiography (QCA). RESULTS At early study, 17 patients (34%) showed a vasoconstriction after maximal dose of ACh (-13.3 +/- 13%) indicative of endothelial dysfunction. Logistic regression analysis identified the following variables as independent predictors of early endothelial dysfunction: donor inotropic support (p = 0.004), female donor (p = 0.04) and rejection at the time of the study (p = 0.01). Forty-one patients were re-studied at follow-up. Nine of them (22%) presented endothelial dysfunction. Early endothelial dysfunction was restored in 6 patients (43%) at follow-up. The number of episodes of rejection was the only variable associated to late endothelial dysfunction. CONCLUSIONS Endothelial dysfunction is a common finding after cardiac transplantation. The pathogenesis of this functional disturbance appears to be donor-related and immune-mediated. The reversibility of this phenomenon observed at follow-up suggests the episodic nature of the immunologic injury.

Tratamiento de la reestenosis intra-stent. Situación actual y perspectivas futuras

In-stent restenosis is an increasing problem due to the frequent use of coronary stent as a form of percutaneous revascularization. The global incidence is near to 28%, and it is well document that a neointimal hyperplasia is its principal mechanism. The most commonly related factors for its appearance are diabetes mellitus, a longer length of the original lesion, a smaller diameter of the reference vessel, the left anterior descending artery location and a smaller luminal diameter at the end of the procedure. Due to a different long term evolution in-stent restenosis has been classified as focal or diffuse, according to the length of the restenotic lesion (focal or = 10 mm). Some strategies have been proven for its treatment, but no randomized-controlled trials have been published comparing these different treatments. In focal in-stent restenosis the practice of a conventional balloon angioplasty is associated with high initial clinical success with a favourable long term evolution (target lesion revascularization between 11-15%). But on the contrary, in diffuse in-stent restenosis, in spite of a high initial success rate, an elevated target lesion revascularization has been detected at the follow-up (up to 43%). Other proved such as atherectomy or excimer laser are associated with a significant procedural non-Q-wave infarction (near to 9%) and a long term target lesion revascularization during follow-up (23-31%). The implantation of an additional stent has been performed with low procedural complications and with a long term target lesion revascularization near to 27%. Patients treated with intracoronary radiation as a complementary technique seem to have a better long term evolution than those having had the other strategies alone. In conclusion, in-stent-restenosis is a new and progressively more frequent problem, requiring complex treatment and of which as been established. Comparative controlled studies need to be performed in order to determine the best treatment for this new entity.

Penetrating aortic ulcer: Clinical and angiographic characteristics

Abstract“Penetrating aortic ulcer,” an atherosclerotic lesion with ulceration that penetrates the internal elastic lamina and allows hematoma formation within the aortic wall, is rarely considered in the differential diagnosis of patients with sudden onset of severe chest or back pain. It has been suggested that it is a pathologic process that involves elderly hypertensive patients with severe atherosclerosis and rarely has been observed in the ascending aorta. To determine the characteristics of this process, 11 clinical, 2 hemodynamic, 3 angiographic, and 4 surgical variables were compared between 10 consecutive patients with penetrating aortic ulcers and 20 matched patients with classic acute aortic dissection. Clinical and hemodynamic variables were similar in the two compared groups. In the group of patients with penetrating ulcer, mean age was 58±6 years, previous hypertension was observed in six patients and the penetrating ulcer was located in the ascending aorta in six cases. Compared with patients with aortic dissection, more angiographic projections were necessary to obtain the diagnosis in the group of patients with penetrating ulcer (2.4±0.8 vs 1.7±0.6;p<0.05). In addition, the presence of angiographic aortic valve regurgitation was only observed in the group of patients with acute dissection (60% vs 0%;p<0.01). Severe atherosclerosis was not present angiographically in any patient with penetrating ulcer. In conclusion, penetrating aortic ulcer can also affect middle-age patients without severe atherosclerosis and is frequently observed in the ascending aorta. Its form of presentation and clinical characteristics are similar to classic aortic dissection. The lack of confirmatory evidence of dissection with suggestive clinical history should raise the possibility of penetrating aortic ulcer.